IMP3 Expression in Borderline Tumors of the Ovary.

Abstract

Borderline ovarian tumors (BOTs) have a less aggressive behavior than invasive epithelial ovarian tumors. Still some patients relapse or succumb to disease. Molecular markers that reliably predict prognosis are lacking. Insulin-like growth factor II mRNA-binding protein (IMP3) has been suggested as a prognostic marker in colorectal, hepatocellular, and ovarian clear-cell carcinomas. We analyzed the expression of IMP3 by immunohistochemistry in a cohort of 140 BOT and its association with histopathological features. We found no association of IMP3 expression with patients' age, FIGO stage, microinvasion, and presence of implants. In contrast, IMP3 expression correlated to mucinous subtype of BOTs (42.2% vs. 9.5% among other subtypes) (p<0.001). IMP3 expression was found to be associated with the presence of in situ carcinoma in MBOT, but not in other subtypes (p=0.021). Expression of IMP3 in BOT is associated with the mucinous subtype and may serve as an early indicator for the development of malignant features.